<div style="text-align:center; width:300px;">

  <form id="form1" name="form1" method="post" action="post.php">
  <table border="0" cellpadding="3" cellspacing="3" style="margin:0 auto;" >
  <tr>
    <td><label>用户名</label>
      :</td>
    <td><input name="Username" type="text" size="20"></td>
  </tr>

  <tr>
    <td><label>密码</label>

      :</td>
    <td><input name="Password" type="text" size="20"></td>
  </tr>
</table>
  </form>

</div>
